NCPP “ QED”Workshop 24 August 2013 Boulder, CO

1. Andrea J. Ray, Ph.D.,NOAA Earth System Research Lab Thanks to: P. Shafroth, L Perry, Amy Symstad, J. Morisette, North Central Climate Science Center Evaluating gridded observations: questions from the NC-CSC NCPP “QED”Workshop 24 August 2013 Boulder, CO 1

2. Many different “gridded observational datasets” • PRISM • CRU (Climate Research Unit, Univ East Anglia) • Daymet • WorldClim • Maurer BCCA & BCSD • Rehfeldt – USFS • NARR = NOAA/NCAR North American Regional Reanalyses • Compare results from different p? • Compare results from different

3. Riparian corridors (Shafroth, Perry, Hay) • Research Question: Will warming decouple the timing of seed dispersal from spring floods? • Cottonwood &willow seed dispersal typically occurs during or just after snowmelt peak flows; flowering determined by accumulated chilling/forcing temperature units • Seed dispersal during or just after the spring flood = • exposed, bare, moist soil in the recruitment band • Too high: dessicate • Too low, scoured away • “just right” Too high – drought stress Receding spring flood Recruitment band Too low – ice and flood scour Base flow

4. Riparian corridors Need to calculate “chilling” and “forcing” units for budburst from temperature Need daily data, not (readily) available from PRISM, so choose DAYMET Streamflow studies using PRISM and Maurer How does DAYMET compare to PRISM? How will streamflow results calculated with PRISM compare? Streamflow based on PRISM Phenology based on Daymet ???? 4 4 4

5. Daymetvs PRISM • Daymet generally warmer, but not consistently across these sites WY NE CO

6. Mean Monthly Runoff in the South Platte 1982-1999

7. Gridded observational data • Multiple gridded observational datasets exist • They’re all slightly different representations of reality • Perry found a nearly 2C difference between DAYMET and PRISM for her sites (not shown) • Solution? Plot them for your area, compare to your data – know what you’re working with • Related question: what if your observations don’t match?

8. Overall objective: to develop “Reasonably Foreseeable Climate Scenarios” (RFCS), based on analysis and comparison among several climate projection datasets and to compare the RFCS to the historic period for the region Support development of risks of climate change to Wyoming ecoregions, conservation elements and key plant and animal species Two year time line for report, take advantage of existing studies, little funding for new work. BLM-WY wants to take advantage of ecological modeling done by Rehfelt et al (USFS) done based on their own statistical downscaling National BLM requires consideration of Hostetler dynamical downscaling Question: How do the statistical downscaling by Rehfeldt and the dynamical downscaling by Hostetler Start with how Rehfeldt’s gridded obs compare to Hostetler’s simulation BLM Wyoming Basin Rapid Ecoregional Assessment

10. Questions on “gridded observational datasets” • Need consistency – or at least an understanding of bias to integrate results from different parts of studies? • Riparian forests example • Need consistency – or at least an understanding of bias compare existing results from different studies being aggregated into an assessment • Wyoming Basin REA example

12. Challenge: Comparing results from different GCMs & their downscaling • Many ecological and hydrological studies published – the basis for work like REAs • Each have made choices, sometimes arbitrary -- but how to compare results • WY REA, for example wants to use Rehfeldt, but he downscaled different GCMs from Hostetler, which they’re required to consider • Solution? • We’re comparing Hostetler & Rehfeldt downscaling for particular variables • If the variables themselves have differences, e.g. warmer/cooler/drier, we’ll have documented the source • Another solution: Consider products that have been used/evaluated in many projects • Statistical products: • “Maurer” – the basis for the Reclamation “SECURE Water Act” report,andextensively analyzed – IMHO the gold standard for now – downscaled many GCMS and ensemble members/GCM; has been run thru a hydrologic model, so available for hydroclimate variables; already being used in DOI policy & planning. Available from several portals, with visualization tools Climate Wizard, GeoDataPortal • Other options: Hayhoe’s downscaling to stations & other products, used in the National Climate Assessment; WorldClim– widely used, less evaluated • Dynamical products covering North America • NARCCAP, North American Regional Climate Change Assessment Program, http://www.narccap.ucar.edu. IMHO the gold standard for now – 6 GCMs and multiple RCMs; used in the 2013 National Climate Assessment • Other options: Hostetler, aka “USGS Dynamical downscaling,” http://pubs.usgs.gov/of/2011/1238/; http://regclim.coas.oregonstate.edu; caveat: only 3 GCMs, 1RCM; BLM requiringitsuse in REAs*

13. Down-scaled climate simulations -- recent conditions

14. Andrea J. Ray, Ph.D., Jeffrey T. Morisette, Dennis Ojima NOAA Earth System Research Lab, NC-CSC, CSU. Thanks to: Amy Symstad, DonimiqueBachelet, P. Shafroth, L Perry, Max Post Van der Berg, Brant Liebmann, Joe Barsugli, Jeff Morisette, Dennis Ojima Delivering climate projections on regional scales to support adaptation planning: ESRL/PSD activities Climate Predictions Applications Workshop 24 April 2013 Logan, UT 14

15. EXTRAS

16. “Tiles” • Ecologists • Edge effects • Solution????

17. “DAYMET vs prism” • Can’t copy laura’s figure? • Edge effects • Solution????

18. “DRAFT” • Ecologists • Edge effects • Solution????

19. General questions/needs across the projects • Climate projections & gridded observational data are widely available from multiple sites • However, little consistent information on evaluations, guidance on use, or “translational information” • Give them the same critical eye as ecological data you use – PLOT & explore the data just as you would biological data {GRAPHIC from daymet and from Laura} • Climate scientists need to do a better job of explaining what different products should and shouldn’t be used for. • Results of objective & quantitative evaluation • Narratives, which may include qualitative and quantitative aspects of data use; e.g., expert guidance on the suitability of the data for an application; also narratives that provide summary information of how the climate has changed or how it will change • Guidance on appropriate uses & interpretation • Characterize & interpret uncertainty • “Time series” data into the future, using the projections as “predictions” • The sequence of events matters for a lot of ecological studies -- Neither ensemble means or simply selecting one or a few runs is a good choice • GRAPHIC Hostetler/USGS Dynamical Downscaling – being used a lot in ecological studies • how do the 3 GCM selected runs compare {GRAPHIC} • Consider this for any GCMS your project is using • Comparing results among available analysis projects • “situate” one or more models in the context of others (Lukas’ Mauer plots)

20. Ecologist’s questions Scale – temporal and spatial • Downscale to very fine resolution, 1km – but is the fine scale actually adding value? Meaningful? • Bioclim indices – widely used, but do the 30 year averages “wash out” extremes and variability that’s an important feature in the • Climate often used“uncritically” • Table with hostetler, rehfeldt, mauerer, MACA/Abatzoglu,Stammetc and whith models downscaled